Meta Platforms said on Friday it struck 20-year agreements to buy power from three Vistra nuclear plants in the U.S. heartland and develop projects with two companies hoping to build small modular reactors.

Meta will also help develop small modular reactors planned by Oklo and TerraPower, the latter of which is backed by billionaire Bill Gates.

Shares of Vistra Energy, Oklo rose about 14% on the news. Other nuclear stocks also jumped with Lightbridge, NuScale Power, Centrus up about 6%.

Meta and other Big Tech companies want to secure long-term electricity supplies as artificial intelligence and data centers increase U.S. power demand for the first time in two decades.

The company said in a blog it will purchase power from Vistra's Perry and Davis-Besse plants in Ohio and Beaver Valley plant in Pennsylvania.

Meta said the deal will help finance expansion at the Ohio plants and lengthen the lifespan of the plants, which are licensed to run through at least 2036 with one of two reactors at Beaver Valley licensed through 2047.

SMR backers say the reactors will one day save costs because they can be built in factories instead of on site. Critics say they will struggle to achieve economies of scale similar to current large reactors. There are no U.S. SMRs in commercial operations yet and the plants will require permits.

Joel Kaplan, Meta's chief global affairs officer, said the plans along with its agreement last year with Constellation to keep an Illinois reactor operating for 20 years, will "make Meta one of the most significant corporate purchasers of nuclear energy in American history."

The agreements will provide up to 6.6 gigawatts of nuclear power by 2035, Meta said. The size of a typical nuclear power plant is about 1 GW. In 2024 Meta sought interest from nuclear power developers for 1 to 4 gigawatts of nuclear power.

Meta will help fund TerraPower's development of two reactors to generate up to 690 megawatts of power as early as 2032. The agreement also provides Meta with rights for energy from up to six other TerraPower reactors by 2035. TerraPower President and CEO Chris Levesque said the agreement will support rapid deployment of reactors.

Meta said its partnership with Oklo will help develop up to 1.2 GW of energy in Ohio as early as 2030. The support will help "early procurement and development" said Jacob DeWitte, Oklo’s co-founder and CEO.